8.3 Column & Beam Schedules

Column & Beam Schedules Overview

While framing plans provide the horizontal layout of a structure, schedules organize detailed information about repetitive vertical and horizontal members into an efficient, tabular format. For the special inspector, understanding how to read column and beam schedules is vital for verifying member sizes, splice locations, connections, and orientations.

Reading Column Schedules

A column schedule provides a comprehensive overview of every column in the building, viewed from the foundation up to the roof. Columns are typically grouped by their grid line intersections (e.g., Column A-1, Column C-4).

Because buildings are often multiple stories tall, a single continuous column cannot be shipped or erected. Therefore, columns are erected in vertical sections called tiers, which usually span two or three floors.

Tier Breaks and Splice Locations

The column schedule explicitly shows the elevations of the floor levels and the locations of the column splices (tier breaks). A standard column splice is located approximately 4 feet to 5 feet above the finished floor elevation. This height allows ironworkers to safely make the bolted or welded connection without having to work on ladders or scaffolding immediately at the floor edge.

The schedule will detail the column size for each tier. For a high-rise building, a column at the base (Tier 1) carries massive loads and might be a heavy built-up section or a massive wide-flange member like a W14x398. As the column progresses upward to Tier 2 and Tier 3, the accumulated load decreases, and the schedule will show lighter column sizes, such as a W14x132 or W14x90. The inspector must verify that the correct sized column is installed in the correct tier.

Column Types and Base Elevations

The schedule identifies the shape of the column: W-shapes, Hollow Structural Sections (HSS), or custom built-up plate columns. At the very bottom of the schedule, the base plate elevation is provided, along with a reference to the base plate detail. This dictates the elevation at which the anchor rods must be set and the grout pad poured.

Orientation of Column Web and Flanges

One of the most critical pieces of information derived from a column schedule (and cross-referenced with the framing plan) is the column orientation. Wide-flange columns have a strong axis (the x-x axis, perpendicular to the web and parallel to the flanges) and a weak axis (the y-y axis, parallel to the web). The structural engineer designs the building relying on the column being oriented in a specific direction to resist lateral loads.

The schedule or framing plan will include a symbol, often an "I" or "H" shape, next to the column grid intersection, indicating the direction of the web. For example, if the web is drawn parallel to grid line A, installing the column rotated 90 degrees so the web is parallel to grid line 1 is a catastrophic error. The inspector must verify the web orientation of every column during the plumbing and alignment inspection.

Sample Structural Column Schedule

Beam Schedules

While primary framing members are often labeled directly on the framing plan, projects with many repetitive beams or complex floor systems often utilize a beam schedule. Instead of cluttering the drawing with text, the plan will simply assign a mark (e.g., B1, B2, B3) to a beam, and the inspector must refer to the beam schedule to find the details.

Span Lengths, Reactions, and Connections

A beam schedule typically includes columns for the member mark, the structural shape (e.g., W21x50), and the span length. Crucially, the schedule provides the end reactions—the shear forces (in kips) that the connection must be designed to support.

If the project uses standardized connection tables (where the fabricator selects the connection based on the load), the inspector uses the reaction load from the schedule to verify that the fabricator detailed a connection with sufficient bolts or weld length. The schedule may also indicate if the beam requires a moment connection (M.C.) at one or both ends.

Camber Requirements

Long-span beams often deflect (sag) under the weight of the wet concrete slab. To counteract this, beams are sometimes cambered—bent slightly upward during fabrication so that they become perfectly flat once the concrete is poured.

The beam schedule will have a column for camber, listed in fractions of an inch (e.g., 3/4", 1-1/2"). When a beam arrives on site, the inspector must verify that it possesses the required camber and, crucially, that the ironworkers erect it with the camber arching upward, not downward.

Composite Stud Callouts

In composite steel construction, shear studs (Nelson studs) are welded to the top flange of the beam. These studs become embedded in the concrete slab, locking the steel and concrete together to act as a single structural unit.

The beam schedule specifies the quantity and spacing of these studs. A callout might read 24 - 3/4"Ø x 4-1/2", meaning 24 studs, each 3/4 inch in diameter and 4-1/2 inches long, are required on that specific beam. The schedule might also dictate the distribution, such as "uniformly spaced" or "12 studs per half-span." The inspector uses this schedule to perform the pre-pour inspection, ensuring every beam has the correct number, size, and spacing of welded shear studs before the concrete is placed.

Sample Structural Beam Schedule